* {
	border: 0;
	box-sizing: border-box;
	margin: 0;
	padding: 0;
}
:root {
	--hue: 223;
	--bg: hsl(var(--hue),10%,90%);
	--fg: hsl(var(--hue),10%,10%);
	font-size: calc(16px + (24 - 16) * (100vw - 320px) / (1280 - 320));
}
body, button {
	color: var(--fg);
	font: 1em/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
body {
	background-color: var(--bg);
	height: 100vh;
	display: grid;
	place-items: center;
}

.progress-clock {
	display: grid;
	justify-content: center;
	align-content: center;
	position: relative;
	text-align: center;
	width: 16em;
	height: 16em;
}
.progress-clock__time-date,
.progress-clock__time-digit,
.progress-clock__time-colon,
.progress-clock__time-ampm {
	transition: color 0.2s linear;
	-webkit-user-select: none;
	-moz-user-select: none;
	user-select: none;
}
.progress-clock__time-date,
.progress-clock__time-digit {
	background: transparent;
}
.progress-clock__time-date,
.progress-clock__time-ampm {
	grid-column: 1 / 6;
}
.progress-clock__time-date {
	font-size: 0.75em;
	line-height: 1.33;
}
.progress-clock__time-digit,
.progress-clock__time-colon {
	font-size: 2em;
	font-weight: 400;
	grid-row: 2;
}
.progress-clock__time-colon {
	line-height: 1.275;
}
.progress-clock__time-ampm {
	cursor: default;
	grid-row: 3;
}
.progress-clock__rings {
	display: block;
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	z-index: -1;
}
.progress-clock__ring {
	opacity: 0.1;
}
.progress-clock__ring-fill {
	transition:
		opacity 0s 0.3s linear,
		stroke-dashoffset 0.3s ease-in-out;
}
.progress-clock__ring-fill--360 {
	opacity: 0;
	stroke-dashoffset: 0;
	transition-duration: 0.3s;
}
[data-group]:focus {
	outline: transparent;
}
[data-units] {
	transition: opacity 0.2s linear;
}
[data-group="d"]:focus,
[data-group="d"]:hover {
	color: hsl(333,90%,55%);
}
[data-group="h"]:focus,
[data-group="h"]:hover {
	color: hsl(33,90%,55%);
}
[data-group="m"]:focus,
[data-group="m"]:hover {
	color: hsl(213,90%,55%);
}
[data-group="s"]:focus,
[data-group="s"]:hover {
	color: hsl(273,90%,55%);
}
[data-group]:focus ~ .progress-clock__rings [data-units],
[data-group]:hover ~ .progress-clock__rings [data-units] {
	opacity: 0.2;
}
[data-group="d"]:focus ~ .progress-clock__rings [data-units="d"],
[data-group="d"]:hover ~ .progress-clock__rings [data-units="d"],
[data-group="h"]:focus ~ .progress-clock__rings [data-units="h"],
[data-group="h"]:hover ~ .progress-clock__rings [data-units="h"],
[data-group="m"]:focus ~ .progress-clock__rings [data-units="m"],
[data-group="m"]:hover ~ .progress-clock__rings [data-units="m"],
[data-group="s"]:focus ~ .progress-clock__rings [data-units="s"],
[data-group="s"]:hover ~ .progress-clock__rings [data-units="s"] {
	opacity: 1;
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
	:root {
		--bg: hsl(var(--hue),10%,10%);
		--fg: hsl(var(--hue),10%,90%);
	}
	.progress-clock__ring {
		opacity: 0.2;
	}
}